/*
自己选择的路 ,跪着也要走完。朋友们 , 虽然这个世界日益浮躁起来,只
要能够为了当时纯粹的梦想和感动坚持努力下去 , 不管其它人怎么样,我
们也能够保持自己的本色走下去。
To the world , you will be a person , but to a person , you
will be the world .                               ——AKPower
*/
#include <iostream>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <vector>
#include <map>
#include <queue>
#include <cstdio>
#include <string>
#include <stack>
#include <set>
#define IOS ios::sync_with_stdio(false), cin.tie(0)
using namespace std;
typedef long long ll;
const ll maxn = 101000;
const ll INF = 1000000000000;
ll d[maxn<<1],a[maxn];
ll n,m,w;

bool judge(ll num){
    memset(d, 0, sizeof(d));
    ll i, pre = 0,cnt=m;
    for (i=1;i<=n;i++){
        ll now = a[i] + pre + d[i];
        if(now<num){
            cnt-=(num-now);
            d[i] += (num - now);
            d[i + w] += (now - num);
        }
        pre += d[i];
    }
    return cnt < 0 ? false : true;
}

    int main()
{
    IOS;
    cin>>n>>m>>w;
    ll minn = INF;
    for (ll i=1;i<=n;i++){
        cin >> a[i];
        minn = min(minn, a[i]);
    }
    ll l = minn,r=minn+m;
    // cout << l << " " << r << endl;
    ll ans = minn;
    while(l<=r){
        ll mid = (l + r) >> 1;
        if(judge(mid)){
            ans = max(ans, mid);
            l = mid + 1;
        }
        else {
            r = mid - 1;
        }
    }
    cout << ans << endl;
    getchar();
    getchar();
    return 0;
}
